People line up in San Francisco, California. They want to see—and smell—a corpse flower.

Yep, a corpse flower. The tropical flower opens just once every several years. And it smells as bad as it sounds.

This particular specimen also has a nickname: Mirage. Mirage began blooming last Tuesday afternoon at the California Academy of Sciences. That’s a special occasion. The plant blooms for one to three days once every seven to 10 years!

During the bloom, Mirage releases a powerful smell. Sniffers compare its stench to rotting food or sweaty socks. The plant smells a bit like a dead carcass. That attracts flies. The flies pick up pollen.

Mirage was donated to the California Academy of Sciences in 2017. This is its first bloom.

Monica Becker took her child out of school to see the flower in person. When she heard about the bloom, she decided to go as soon as the California Academy of Sciences opened the next morning. “So here we are,” she says. (Would you like to take a field trip to get a whiff of Mirage?)

“I definitely picked up on the sweaty socks [and] sweaty gym clothes,” says visitor Bri Lister. “Definitely a smellier plant than average.”

The flower is native to the Indonesian island of Sumatra. Fewer than 1,000 individual plants remain in the wild.

And God said, “Behold, I have given you every plant yielding seed that is on the face of all the Earth.” — Genesis 1:29